This paper presents a novel approach that can compensate errors resulting from the imperfections of mechanical structures and interface circuits for MEMS gyroscope systems. The mechanical structure errors discussed in this paper contribute to unknown proof mass, spring constants, damping coefficients, and existence of cross-axis resilient/damping forces. The interface circuit errors include: mismatch of differential capacitors, parasitic capacitance, offset voltage of operation amplifiers, and circuit noise. Different from most of existing researches, the proposed method has the following features: (1) the mechanical structure imperfections and interface circuit errors are compensated simultaneously using control techniques; (2) the mass of the proof mass can be unknown. This approach is verified on two types of gyroscope designs by numerical simulations. Simulation results indicate that, under those imperfections, the proposed method can obtain correct angular rate within 80 milliseconds.